A wide range of neurological diseases and disorders exist that are not well addressed by present medical technology. Among these, dysphagia is a particularly life threatening disorder placing persons at risk of aspiration pneumonia. Patients at risk of aspiration pneumonia have a 17% survival rate over three years (Pick et al., 1996). Estimates are that over 3 million persons in the U.S. have dysphagia as a result of neurological diseases or disorders such as stroke, traumatic brain injury, brain tumors, Parkinson's disease, multiple sclerosis and other neurological diseases and over 300,000 persons develop a swallowing disorder as a result of a neurological disease or disorder in the United States each year. Over 50% of patients with neurological diseases or disorders are at risk of aspiration pneumonia because of loss of central nervous system control of their swallowing resulting in either delayed or reduced elevation of the hyolaryngeal complex, which does not allow them to prevent food or liquid from entering the airway (Lundy et al., 1999). Normally the hyoid and larynx are raised by about 20 mm during swallowing producing an inversion of the epiglottis and assisting with opening of the upper esophageal sphincter. Many therapeutic techniques aim to improve hyolaryngeal elevation and reduce aspiration risk in dysphagia (Logemann, 1998).
Many other disorders need treatment, particularly as a result of stroke and other neurological diseases. In addressing these treatment needs, research has demonstrated that somatosensory stimulation can potentiate recovery of hand movement post stroke (e.g., Conforto, et al. 2002; van Dijk et al., 2002; Struppler et al., 2003; Peurala et al., 2002).
Others have shown that somatosensory stimulation applied to a paretic hand has transient beneficial effects on the paretic hand pinch force (Conforto, Kaelin-Lang, & Cohen, 2002) in patients with stroke. It has previously been shown that electrical stimulation to the faucial pillars in the mouth can trigger swallowing (Pommerenke, 1927) while laryngeal sensory blocks will severely impair volitional swallowing in normal adults (Jafari, Prince, Kim, & Paydarfar, 2003). Pharyngeal stimulation can initiate laryngeal closure and elevation for swallowing in animals (Jean, 1984), while laryngeal stimulation will trigger a swallow (Nishino, Tagaito, & Isono, 1996). In humans, when sensory stimulation of the oropharynx is presented during a period separate from swallowing, it enhances cortical activity in the swallowing regions (Fraser et al., 2003; Hamdy et al., 2003; M. Power et al., 2004), but does not benefit subsequent swallowing in dysphagic patients (M. L. Power et al., 2006). Thus, further discoveries are needed in this area.
Broad methods and devices are presented for therapy of neuromuscular disorders such as dysphagia. With training, severely dysphagia patients can learn to coordinate neuromuscular stimulation onset during their swallowing significantly reducing their aspiration risk. This is illustrated in FIG. 3. By training patients to coordinate their own swallowing with stimulation, their central volitional control was found to also improve significantly (p=0.0025), without stimulation post-training. This is illustrated in FIG. 4. Subjects could improve quickly in their ability to trigger stimulation at the same time as intending to swallow. Other results indicate that normal persons can easily and spontaneously coordinate the onset of a button press with the onset of muscle activation for the pharyngeal component of swallowing (Burnett et al., 2005). Accordingly, patients with dysphagia can learn to coordinate a muscular movement such as a button press with swallowing onset. (C. L. Ludlow et al., 2005) In other embodiments, other muscle movements similarly are quickly learned in a similar manner.